Inspiron 7490 BIOS: How to turn off intel 'RAID on', and swith disk mode to AHCI?

Our support is limited to Windows 10 on this Inspiron 7490. This is proven when you go to the Inspiron 7490 driver page and check the "Operating system". It only shows Windows 10, 64-bit.

@DELL-Cares  I'm sorry, but this isn't just a case of offering limited Linux support.  Limited support would imply that customers who wanted to run Linux might still be able to figure out their own workarounds or accept certain limitations.  But not offering AHCI mode makes it completely impossible to run Linux.  In addition, not offering support for AHCI mode creates problems even for some Windows scenarios.  For example, a Windows user with a Samsung SSD might want to use the Samsung NVMe driver instead of Microsoft's built-in NVMe driver, but that requires the system to be in AHCI mode.  When the system is in RAID mode, the only driver that can (and must) be used is Intel's RST driver.  It makes no sense to me why Dell would force RAID mode to be enabled on these systems without an option to use AHCI mode that disables the Intel RST controller.

Well, the only thing I can see is that the advertised OS  is only Windows 10, this is a business-class notebook intended for business use. So there would be no reason to support Ubuntu as it is not used for business purposes.

They do not specify that AHCI is not available either.

The reasonIRST is used I assume it that is compatible with all drives and Windows systems If you choose Apple products you use what Apple allows you know this since you moved from Apple products.

I also would assume if Dell were to get enough people complaining that AHCI is not available, they would then rewrite the UEFI/BIOS 

@Mykey77777  if Linux is important to you, I would return this system, because it's not clear whether Dell will fix this, and since Dell never officially advertised Linux compatibility, you probably wouldn't be able to return it beyond the official return period for this reason.

@Clintlgm  it's not correct to claim that Ubuntu isn't used for business purposes.  Linux is absolutely used within businesses, and Ubuntu is a popular distro.  Not everyone in the business world uses Windows or macOS.  In addition, since we're talking about an Inspiron 7490 here, this is NOT in fact a business-class system aimed at business users -- that would be a Latitude, Precision, XPS, or Vostro system.  The Inspiron systems are aimed at consumers.  In any case, Dell does default to using RST/RAID mode because it's the most compatible setup for Windows, but it's still unusual that they wouldn't offer a way to disable it, which they've always offered in the past for the very long time that RST/RAID mode has existed already.  I would be surprised if there was a technical reason that this particular system REQUIRED the RST/RAID controller to be enabled, so my guess is that this is a bug/oversight, but we're not getting an official answer here.  In any case, it's completely understandable to want and expect that this system would have an AHCI option, because every other Dell and non-Dell system I've seen or read about has had it, since that's the "normal" mode that exposes the raw storage interfaces to teh OS without involving any special controller as RAID mode does.

Sorry for the confusion, I only looked up 7490 didn't realize that the same model numbers are used with both Inspiron and Latitude.

Same problem. Also in Dell's webpage : 

https://www.dell.com/support/article/tw/zh/twdhs1/sln308883/how-to-resolve-an-pcie-nvme-m-2-ssd-ubuntu-kubuntu-installation-problem-on-your-dell-pc?lang=en

"The SSD is detected in the BIOS (Basic Input/Output System), which is set to AHCI (Advanced Host Controller Interface) with Secure Boot disabled."

We need the approach to set to AHCI in BIOS for Ubuntu installation as before. 

Hope can add AHCI mode for SATA back to the BIOS of Dell Inspiration 7490. 

( I bought this to install/use Linux system, and now stuck..  )

Same problem here ! Please bring back AHCI option in the next BIOS update.

Just got my Dell G7 7588 this afternoon(12 hours ago).Right now I need to figure out why I cant start windows using my 500gb solid state from my previous laptop. after changing a lot of settings in bios. I was able to switch it from RAID to AHCI.

Now the only way i can get my 500gb SSD (win 10 os) to work on this laptop is by starting windows through the128GB M.2 PCIe NVMe and accessing my 500gb SSD like any other extra storage HD. 

The problem is the 128GB solid-state has the C: drive label claimed because the M2 SSD slot is labeled as SATA1 and the 2.5 Hard Drive slot is labeled SATA0 in the motherboards firmware.

(i did not take this photo) shows m2 128gb ssd in red square.

  Even when I remove that 128gb drive and only use my 500gb SSD, it gives me boot errors since the 500gb drive is labeled as D & E Drive. also tried resetting the clock and powering on the laptop with only the 500gb installed and no luck. 

 This doesn't solve your problem, but it does tell you what has been attempted.

best of luck,

staticx720

Just got my Inspiron 7490 and couldn't get linux to install and now I see the reason. Looks like it will have to go back which is a shame. I've never even considered that any Dell laptops wouldn't work as I've never had any problems before now I'm wondering just how many of their new laptops are the same. This is putting me off Dell now as I now can't be sure if the new release laptops I get will allow linux to get installed. I think there is little point in contacting support as they never tell you what their plans are anyway so I doubt I'll get a coherent response regarding whether they will enable AHCI support or not.

I share the overall discomtempt of people on this thread.

Also bought this laptop having in mind the good reptation Dell had, thinking that I would be able to install a Linux distro on it. Now I see Dell went as far as possible to make this a not possibility. In the meantime when all these people complained you could have released a new BIOS that solved this problem, but you decided not to. It's a conscious policy, not an accident. You just sent a message to Linux users that Dell is not their friend.

Unless I hear an official notice in the following days with options for me to use AHCI and install Linux on my laptop I'm going to return this, ask for a refund and maybe not buying Dell again.. This is extremely sad, as I said, since I had the impression before of Dell having a good reputation to be Linux-friendly, and this laptop in particular looked quite nice overall.

Extremely stressful

Just would like to share my experience. 

I struggled with this issue to install ubuntu and finally I installed and run Linux by using external usb disk. It's not so slow as I imaged before, and I can accept it. Though Dell also suggested other model which can support AHCI, but I likes the shape, the weight (it's really light), the CPU speed (intel 10th i7), and wifi6 of Inspiron 7490  ^^ FYI. 

After a frustrating time trying to get linux installed only find this and confirm what I thought it just isn't possible I thought I'd give a spare ssd and a spare 2.5" enclosure a go and run that off USB and to my surprise it working really well. I actually don't notice any issues so happy enough. No idea how it compares to native but I've no chance of finding that out. Only been using it today so not long enough to come to a firm conclusion. If all works well I'll probably trade this setup with one of the nvme ssd cards and enclosures as they are bit more compact and if I get a docking station anyway I could run that all of thunderbolt. Only time will tell.

Just want to add that I face the same problem. It seems that it is not very difficult to rewrite BIOS so it would support AHCI. Maybe somebody could do it and make life much easier for hundreds of people? We will appreciate it a lot. Thanks;)

To my knowledge, Dell systems will only accept BIOS code that has been digitally signed by Dell specifically to prevent hacked firmware that might have been modified maliciously. So even if someone had the skills to decompile BIOS code and modify it appropriately, getting systems to accept it would be difficult at best.